Hi SimonSure they do.For info, I have a solar panel of 80W which is far enough for my use (daily trip, using VHF, pilot, GPS, ampli for music with a single battery). I never plug the boat.If you race day and nigth, as the mini circuit, they have 2 batteries, and most of them now have only solar panels (2 x 50 W, or 2 x 80 W).